AP EAMCET201823 Apr 2018Evening ShiftMathematicsTrigonometric Ratios & IdentitiesActual
In A B C , if 3 A+ 3 B+ 3 C+ 3 =0 , then the least value of the sum of two of its angles is
Options
- A6
- B2 3
- C3
- D4
Correct answer
C. 3
Step-by-step solution
In a A B C , it is given that gathered 3 A+ 3 B+ 3 C+ 3 =0 2 3(A+B) 2 3(A-B) 2 + 3 C-1=0 -2 ( 3 C 2 ) 3(A-B) 2 +1-2 ^2 ( 3 C 2 )-1=0 3 C 2 [ 3(A-B) 2 - 3(A+B) 2 ]=0 3 A 2 3 B 2 3 C 2 =0 Means either A= 2 3 or B= 2 3 or C= 2 3 gathered So, the least value of the sum of two of its angles is - 2 3 = 3